High level of IgG4 as a biomarker for a new subset of inflammatory bowel disease

Zhujun Wang,Yu Zhen,Wenyan Zhang,Jingxi Mu,Qin Ouyang,Chengxin Luo,Hu Zhang,Min Zhu

doi:10.1038/s41598-018-28397-8

Zhujun Wang, Yu Zhen + Show 6 more

Open Access

https://doi.org/10.1038/s41598-018-28397-8

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Abstract

The roles of B and plasma cells in the pathogenesis of inflammatory bowel disease (IBD) are largely unrevealed. Data on the characteristics of IgG4 in patients with IBD are scarce. In this case-control study, serum IgG4 levels were comparable between patients with IBD and healthy individuals, whereas patients with IBD had dramatically higher mucosal IgG4 counts than healthy individuals. In patients with UC, mucosal IgG4 counts were positively correlated with serum IgG4 levels, serum IgG4/IgG ratios, and the Mayo Index; serum IgG4 levels and IgG4/IgG ratios were associated with a history of intestinal surgery and medications. A significant mucosal IgG4 count was found in 33.3% of patients with IBD, whereas, elevated serum IgG4 levels were found in only 9.9% of patients with IBD. Lesions were more severe and extensive in IBD patients with high levels of serum and mucosal IgG4. High levels of serum and mucosal IgG4 decreased after treatment with glucocorticoids or other immunosuppressants. High IgG4 level may be a biomarker for a new subset of IBD. More studies are warranted to explore this new subset of IBD for personalized therapy in the future.

Highlights

Inflammatory bowel disease (IBD), comprising ulcerative colitis (UC) and Crohn’s disease (CD), is a series of nonspecific inflammatory conditions affecting the gastrointestinal tract
Immunohistochemical IgG4 staining found that the infiltration of mucosal IgG4 cells in both patients was dramatically decreased (Fig. 5e,f). This prospective case–control study demonstrated that a small subset of patients with inflammatory bowel disease (IBD) can be characterized by high levels of serum and mucosal IgG4
In patients with UC, mucosal IgG4 counts were positively correlated with serum IgG4 levels quite a number of patients with significant infiltration of IgG4 cells had serum IgG4 concentrations

Summary

Introduction

Inflammatory bowel disease (IBD), comprising ulcerative colitis (UC) and Crohn’s disease (CD), is a series of nonspecific inflammatory conditions affecting the gastrointestinal tract. Rebours et al.[18] compared the infiltration of mucosal IgG4+ plasma cells in intestinal tissues of patients with IBD and patients with autoimmune pancreatitis (AIP). Based on the above evidence, we hypothesized that IBD patients with significant level of serum and/or mucosal IgG4 may possess distinct clinical characteristics and that high level of IgG4 is a biomarker for a new subtype of IBD. We conducted a prospective case–control cohort study characterizing serum IgG4 levels, IgG4/IgG ratios, and infiltration of mucosal IgG4+ plasma cells in Chinese patients with IBD and investigated their associations with clinical characteristics. We identified a small subset of patients with IBD exhibiting high levels of serum and mucosal IgG4, and these patients had their own distinctive clinical features. All the evidence suggests that high level of IgG4 may be a biomarker for a new subtype of IBD

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